Medical upright positioning devices may be used to record x-ray images of a standing patient in predetermined positions. For some applications, it may be necessary to obtain image data from multiple angles (e.g., for the hip area) for later evaluation (e.g., on a computer screen). In standardized evaluation methods, it is possible to roughly plan the treatment in advance with the aid of such image information, e.g., to roughly plan the placement of implants into the image data, wherein implant data may be stored in a computer system.
In order to perform such advance planning steps, however, it should be ensured that during recording, the patient is precisely situated in a desired recording direction, e.g., a first recording directly from the front (anterior-posterior) and a second recording at an angle of 60° to the x-ray film.
Various attempts have been made to achieve said predetermined patient positionings. For example, foils or templates indicating multiple foot positions have been placed on the floor in front of the x-ray film. The patient then may be instructed to position himself on the foot depictions in accordance with the desired position. A disadvantage of such foils or templates is that they are easily moved and therefore have to be re-orientated each time they are used, e.g., by way of a line marked on the floor. If they are not properly re-orientated, the patient position in the x-ray image may be incorrect.
Another approach is to attach to the patient a calibration object that can be depicted in the images. The technique used in this case can be elaborate, and it is possible that the calibration object may move relative to the patient while he is being repositioned. This can lead to imprecise position determinations.
A patient positioning device is known, for example, from U.S. Pat. No. 3,700,894, which comprises foot stoppers attached to rotating bars, and head mounts. The device, however, is in turn configured very elaborately and must permanently remain at its location.